The present disclosure relates to a display device, and is applicable to a display device including a white organic light-emitting diode element, for example.
The organic light-emitting diode (OLED) element is an element that injects positive and negative electric charges into a light emitting layer formed of an organic thin film and converts electric energy into optical energy for emitting light. Since a luminous display device including an organic light-emitting diode element as a light emitting element (in the following, referred to as “an OLED display”) is a self-luminous type, which is different from a non-luminous display device typified by a liquid crystal display device, an auxiliary light source such as a backlight is unnecessary, and the OLED display is reduced in the thickness and in the weight. Moreover, the OLED display has characteristics including a wide viewing angle and a quick display response speed.
Since the OLED has a structure in which thin films of the order of an optical wavelength or less are stacked in the thickness, the OLED is easily affected by optical interference. On this account, when the observation angle is changed, a problem arises in that colors are changed because of the influence of interference. To this problem, a technique is proposed in which such a structure is adopted that the peak wavelength of the intensity of interference is shorter than the peak wavelength of the emission wavelength and changes in colors caused by a difference in the observation angle are suppressed. (See Japanese Unexamined Patent Application Publication No. 2005-31251)